The crank test is performed with the patient in the sitting position (It can be done while the patient is supine).
Their arm is elevated to 160 degrees in the scapular plane of the body and is positioned in maximal internal or ER.
The clinician then applies an axial load along the humerus.
What does a positive Crank Test mean?
Crank Test is Positive when there is clicking or pain in the glenohumeral joint during the maneuver.
Sensitivity & Specificity
A prospective evaluation study 1 found that this test was found to have a high sensitivity and specificity for diagnosing labral tears in a series of 62 patients who presented with shoulder pain that was refractory to 3 months of conservative management:
Sensitivity: 91 %
Specificity: 93 %
A study was done by S H Liu, to compare between magnetic resonance imaging and clinical examinations for diagnosis of glenoid labral tears.
The crank test has been found to have a higher sensitivity (90%) than MRI (59%) and equal specificity (85%) to MRI based on a study to compare between magnetic resonance imaging and clinical examinations for diagnosis of glenoid labral tears.2
What is SLAP Lesion?
SLAP lesions are described as superior labral lesions that are both anterior and posterior.
There are several injury mechanisms that are speculated to be responsible for creating SLAP lesions ranging from single traumatic events to repetitive microtraumatic injuries.
During a dislocation, tears to the glenoid labrum occur in isolation or in combination. The superior aspect of the labrum is more mobile and prone to injury due to its close attachment to the LHB tendon.
The lesion typically results from a FOOSH injury, sudden deceleration or traction forces such as catching a falling heavy object, or chronic anterior and posterior instability.
Snyder and colleagues classified SLAP lesions into four main types by signs and symptoms:
Type I: This type involves a fraying and degeneration of the edge of the superior labrum. The patient loses the ability to horizontally abduct or externally rotate with the forearm pronated without pain.
Type II: This type involves a pathologic detachment of the labrum and biceps tendon anchor, resulting in a loss of the stabilizing effect of the labrum and the biceps.
Type III: This type involves a vertical tear of the labrum, similar to the bucket-handle tear of the knee meniscus, although the remaining portions of the labrum and biceps are intact.
Type IV: This type involves an extension of the bucket handle tear into the biceps tendon, with portions of the labral flap and biceps tendon displaceable into the G-H joint.
Several special tests can be used to help identify the presence of a SLAP lesion including:
S H Liu, M H Henry, S L Nuccion. A prospective evaluation of a new physical examination in predicting glenoid labral tears. Am J Sports Med. Nov-Dec 1996;24(6):721-5. doi: 10.1177/036354659602400604. PMID: 8947391.
Liu SH, Henry MH, Nuccion S, Shapiro MS, Dorey F. Diagnosis of glenoid labral tears. A comparison between magnetic resonance imaging and clinical examinations. Am J Sports Med. 1996 Mar-Apr;24(2):149-54. doi: 10.1177/036354659602400205. PMID: 8775111.
Magnus Arnander and Duncan Tennent. Clinical assessment of the glenoid labrum. Shoulder Elbow. 2014 Oct; 6(4): 291–299. PMID: 27582948.
Clinical Tests for the Musculoskeletal System, Third Edition book.
Mark Dutton, Pt . Dutton’s Orthopaedic Examination, Evaluation, And Intervention, 3rd Edition Book.